1. Field of the Invention
The present invention relates to a treatment tool for an endoscope that is inserted into a body from a channel of the endoscope, extracts cells and tissue at a predetermined region in the body, and performs excision and the like.
Priority is claimed on Japanese Patent Application No. 2005-358561, filed Dec. 13, 2005, the content of which is incorporated herein by reference.
2. Description of Related Art
A treatment tool for an endoscope is used by insertion inside a channel of an endoscope insertion section that has been inserted into a body and protruding/retracting the treatment section from the distal end of the endoscope insertion section.
The endoscope channel is continuous for passage from the distal end of the endoscope insertion section that is positioned in the body to an insertion opening outside of the body at which the endoscope treatment device is inserted.
That is, the endoscope channel is put in the state of making continuous the space at a predetermined region in the body and external space.
In the case of performing observation of a predetermined region with an endoscope and in the case of performing treatment of a predetermined region with the treatment tool for an endoscope, it is necessary to make the air pressure in the body higher than the atmospheric pressure in order to secure the space around the predetermined area.
However, in such a case, bodily fluids and the like in the body may flow backwards through the channel due to the atmospheric-pressure difference of the inside of the body and the outside of the body.
For this reason, a forceps plug formed with rubber or the like is provided at the mouth ring provided at the insertion opening.
A through hole is formed in the center of the forceps plug, and a backflow valve is provided in the through hole.
Due to the back flow valve, the inside of the channel and the inside of the body are separated from the external space.
Also, it is possible to use the treatment tool for an endoscope by inserting the insertion section with a treatment section provided at the distal end from the through hole of the forceps plug into the channel.
As disclosed in Japanese Unexamined Patent Application, First Publication No. H07-178098, as a treatment tool for an endoscope that samples cells and tissue of a predetermined region in a body, a tool for an endoscope is used that is provided with a sheath that has flexibility, an operation section that is provided at the base-end portion of the sheath, a needle tube that is inserted inside the sheath, and a stylet that is inserted inside the needle tube.
In this kind of treatment tool for an endoscope, it is possible to relatively move forward/backward the needle tube and stylet with respect to the sheath by the operation section.
This kind of treatment tool for an endoscope is used by fixing the operation section to a screw that is formed in a mouth ring since accurate operation is required at the predetermined region in the body.